Java设计模式——抽象工厂模式

抽象工厂模式也是创建模式，可以把它理解成创建工厂的工厂，这种模式也是我们经常使用的。
在抽象工厂中的接口是用来创建工厂的，每个生成的工厂又都可以按照工厂模式创建其他对象。

举例说明：

1. 创建Shape接口及其实现类Circle、Square、RoundedRectangle、RoundedSquare
2. 创建抽象工厂类AbstractFactory
3. 创建工厂类ShapeFactory，它继承AbstractFactory抽象类
4. 创建工厂生成类FactoryProducer
5. 创建AbstractFactoryPatternDemo类，用来测试抽象工厂模式

1、创建接口Shape

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public interface Shape {    void draw(); }

2、创建接口Shape实现类

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public class Rectangle implements Shape {    @Override    public void draw() {       System.out.println("Inside Rectangle::draw() method.");    } }   public class Square implements Shape {    @Override    public void draw() {       System.out.println("Inside Square::draw() method.");    } }   public class RoundedRectangle implements Shape {    @Override    public void draw() {       System.out.println("Inside RoundedRectangle::draw() method.");    } }   public class RoundedSquare implements Shape {    @Override    public void draw() {       System.out.println("Inside RoundedSquare::draw() method.");    } }

3、创建抽象类AbstractFactory

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public abstract class AbstractFactory {    abstract Shape getShape(String shapeType) ; }

4、创建抽象类AbstractFactory的实现类

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public class ShapeFactory extends AbstractFactory {    @Override    public Shape getShape(String shapeType){          if(shapeType.equalsIgnoreCase("RECTANGLE")){          return new Rectangle();               }else if(shapeType.equalsIgnoreCase("SQUARE")){          return new Square();       }        return null;    } }   public class RoundedShapeFactory extends AbstractFactory {    @Override    public Shape getShape(String shapeType){          if(shapeType.equalsIgnoreCase("RECTANGLE")){          return new RoundedRectangle();               }else if(shapeType.equalsIgnoreCase("SQUARE")){          return new RoundedSquare();       }        return null;    } }

5、创建工厂生成类FactoryProducer

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public class FactoryProducer {    public static AbstractFactory getFactory(boolean rounded){         if(rounded){          return new RoundedShapeFactory();               }else{          return new ShapeFactory();       }    } }

6、测试

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public class AbstractFactoryPatternDemo {    public static void main(String[] args) {       //get shape factory       AbstractFactory shapeFactory = FactoryProducer.getFactory(false);       //get an object of Shape Rectangle       Shape shape1 = shapeFactory.getShape("RECTANGLE");       //call draw method of Shape Rectangle       shape1.draw();       //get an object of Shape Square       Shape shape2 = shapeFactory.getShape("SQUARE");       //call draw method of Shape Square       shape2.draw();       //get shape factory       AbstractFactory shapeFactory1 = FactoryProducer.getFactory(true);       //get an object of Shape Rectangle       Shape shape3 = shapeFactory1.getShape("RECTANGLE");       //call draw method of Shape Rectangle       shape3.draw();       //get an object of Shape Square       Shape shape4 = shapeFactory1.getShape("SQUARE");       //call draw method of Shape Square       shape4.draw();            } }

7、结果

Inside Rectangle::draw() method.
Inside Square::draw() method.
Inside RoundedRectangle::draw() method.
Inside RoundedSquare::draw() method.